1. Field of the Invention
The present invention relates to a recording head, a substrate for the recording head, and a recording apparatus.
2. Description of the Related Art
As disclosed in publications, for example, Japanese Unexamined Patent Publication No. 05-185594, it is already known that diodes are provided on a base plate of a recording head, such as a liquid-discharging recording head (ink-jet recording head), and matrix-driving is performed for electrothermal conversion elements (heating elements). Also known is that various items, such as electrothermal conversion elements, shift-register sections, latch sections, and logical circuit sections, are formed on the same base plate.
As a prerequisite, the head mentioned above is formed such that the heating elements, the diodes, and the logical circuits are fabricated on a silicon base plate by semiconductor processing (such as ion-plantation processing). Therefore, it is advantageous that a head with a small number of discharging openings can be produced compactly in a single step. However, for example, in a case where a full-line head that has a line of discharging openings which has a length corresponding to the entire width of a recording sheet is produced by integrally fabricating heating elements, diodes, logical circuits, and the like on the same base plate, the base plate itself must be formed larger in proportion to increase in the length of the head. Even in a case where such a head could be produced, since the head would be very large, it would be highly priced. To avoid this, suggestions have been made such that smaller heads are connected, thereby forming a line head. In this case, however, since variation in the position of the individual heads easily occurs, the overall quality levels of the heads are inconsistent.
Accordingly, an object of the present invention is to provide a recording head that allows overall miniaturization and cost reduction to be implemented and that is capable of performing high-quality recording operations
Another object of the invention is to provide a substrate for the aforementioned recording head.
Still another object of the present invention is to provide a recording apparatus.
To these ends, according to one aspect of the present invention, there is provided a recording head comprising a plurality of recording elements provided on a base plate, a plurality of metal-insulator-metal (MIM) elements each corresponding to each of the plurality of recording elements and having an insulating layer and a pair of conductive layers sandwiching the insulating layer, first connecting sections provided for individual groups of the plurality of recording elements, and second connecting sections provided for individual groups of the plurality of MIM elements, wherein the first connecting section and the second connecting section are used to perform matrix-driving for each of the plurality of recording elements, thereby performing recording operations.
According to another aspect of the present invention, there is provided a substrate for a recording-head comprising a plurality of recording elements provided on a base plate, a plurality of metal-insulator-metal (MIM) elements each corresponding to each of the plurality of recording elements and having an insulating layer and a pair of conductive layers sandwiching the insulating layer, first connecting sections provided for individual groups of the plurality of recording elements, and second connecting sections provided for individual groups of the plurality of MIM elements, wherein the first connecting section and the second connecting section are used to perform matrix-driving for each of the plurality of recording elements, thereby performing recording operations.
According to still another aspect of the present invention, there is provided a recording apparatus comprising a recording head and members for mounting the recording head, the recording head comprising a plurality of recording elements provided on a base plate, a plurality of metal-insulator-metal (MIM) elements each corresponding to each of the plurality of recording elements and having an insulating layer and a pair of conductive layers sandwiching the insulating layer, first connecting sections provided for individual groups of the plurality of recording elements, and second connecting sections provided for individual groups of the plurality of MIM elements, wherein the first connecting section and the second connecting section are used to perform matrix-driving for each of the plurality of recording elements, thereby performing recording operations.
According to the present invention, by forming the plurality of recording elements (heating elements) according to thin-film processing on the base plate at least having the surface which serves as an insulator, the recording head having less variation in characteristics for individual discharging openings can be obtained.
Also, by forming the plurality of MIM elements according to thin-film processing similar to that used for the heating elements, the recording head having less variation in characteristics of the MIM elements can be obtained.
In addition, when electrodes connected to the heating elements and the like are arranged so as to be shared by configuration members of the MIM elements, the number of production steps does not need to be so increased that lower-priced recording head can be obtained.
Furthermore, matrix-driving using the MIM elements is effective for miniaturization of the head and cost reduction therefor.
In the present invention, MIM elements may be formed at cross sections of striped lower electrodes and striped upper electrodes. The MIM elements arranged in a matrix are driven such that voltages are applied to the striped lower electrodes and the striped upper electrodes that are in contact with the MIM elements that will be driven, and the difference between the voltages is applied to the MIM elements. In this case, the potential difference is also applied to the MIM elements only on voltage-applied one of the sides of the striped upper electrodes and the striped lower electrodes. However, the absolute value of the potential difference is lower than that of the potential difference applied to the MIM elements on the both voltage-applied electrodes. In the MIM element, the amount of current variation in response to the variation in an applied potential difference is large. Therefore, even when potential differences having absolute values that are lower than the absolute value of the potential difference for producing a predetermined amount of heat, no substantial current is allowed to flow, and no substantial heat is generated. Thus, the amount of unnecessary heat generated by the MIM element not selected is small.
In this case, voltage-applying means need not be provided for the individual MIM elements provided in a matrix as heating means. Therefore, a configuration can be easily made such that a voltage-applying means for applying voltage to the MIM elements is provided outside of the ink-jet recording head, and interface electrode sections removable from the voltage-applying are provided inside of the ink-jet recording head. That is, end sections of the striped lower electrodes, the striped upper electrodes are arranged on peripheral sections of the ink-jet recording head, and these portions are used as the interface electrode sections that are removable from the voltage-applying means. According to this configuration, production costs for the ink-jet recording head that must be replaced when the ink therein runs short can be reduced.
Further objects, features, and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.